When endogenous lung surfactant is deficient or becomes dysfunctional in humans, it can be replaced by exogenous surface-active substitutes. Therapy with active exogenous surfactant drugs has proven to be life-saving in preventing and treating the neonatal respiratory distress syndrome (NRDS) in preterm infants, and on-going research is studying the feasibility of efficaciously extending surfactant therapy to pediatric and adult patients with clinical acute lung injury (ALI) or acute respiratory distress syndrome (ARDS). Developing effective surfactant therapy for ALIIARDS is particularly challenging, and requires the use of exogenous surfactants having maximal surface and pulmonary activity, plus the ability to resist inhibition from endogenous substances present in injured lungs as a result of permeability edema or in association with the inflammatory response.
Synthetic lung surfactants have a number of important advantages over current animal-derived surfactants as pharmaceutical products for treating NRDS and ALI/ARDS. In research on synthetic surfactant development, particular emphasis has been placed on designing peptide mimics of natural surfactant proteins, but more research is needed to identify peptides that are highly effective, stable, and easy to manufacture.